/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/
/****************************************************************************
 * tools/cfgdefine.c
 *
 *   Copyright (C) 2007-2013 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <string.h>
#include <ctype.h>
#include "cfgdefine.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

/****************************************************************************
 * Public Data
 ****************************************************************************/

char line[LINESIZE + 1];

/****************************************************************************
 * Private Data
 ****************************************************************************/

/* These are configuration variable name that are quoted by configuration tool
 * but which must be unquoted when used in C code.
 */

static const char *dequote_list[] = {
	/* TinyAra */

	"CONFIG_USER_ENTRYPOINT",	/* Name of entry point function */
	"CONFIG_EXECFUNCS_SYMTAB",	/* Symbol table used by exec[l|v] */
	"CONFIG_PASS1_TARGET",		/* Pass1 build target */
	"CONFIG_PASS1_OBJECT",		/* Pass1 build object */
	"CONFIG_DEBUG_OPTLEVEL",	/* Custom debug level */
	"CONFIG_INIT_SYMTAB",		/* Global symbol table */
	"CONFIG_INIT_NEXPORTS",		/* Global symbol table size */

	/* RGMP */

	"CONFIG_RGMP_SUBARCH",		/* RGMP sub-architecture */

	/* apps/ definitions */

	"CONFIG_EXAMPLES_HELLO_PROGNAME",	/* Name of installed hello example program */
	"CONFIG_WPA_SUPPLICANT_ENTRYPOINT",	/* Name of entry point function */

	NULL						/* Marks the end of the list */
};

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/* Skip over any spaces */

static char *skip_space(char *ptr)
{
	while (*ptr && isspace((int)*ptr))
		ptr++;
	return ptr;
}

/* Find the end of a variable string */

static char *find_name_end(char *ptr)
{
	while (*ptr && (isalnum((int)*ptr) || *ptr == '_'))
		ptr++;
	return ptr;
}

/* Find the end of a value string */

static char *find_value_end(char *ptr)
{
	while (*ptr && !isspace((int)*ptr)) {
		if (*ptr == '"') {
			do
				ptr++;
			while (*ptr && *ptr != '"');
			if (*ptr)
				ptr++;
		} else {
			do
				ptr++;
			while (*ptr && !isspace((int)*ptr) && *ptr != '"');
		}
	}
	return ptr;
}

/* Read the next line from the configuration file */

static char *read_line(FILE * stream)
{
	char *ptr;

	for (;;) {
		line[LINESIZE] = '\0';
		if (!fgets(line, LINESIZE, stream))
			return NULL;
		else {
			ptr = skip_space(line);
			if (*ptr && *ptr != '#' && *ptr != '\n')
				return ptr;
		}
	}
}

/* Parse the line from the configuration file into a variable name
 * string and a value string.
 */

static void parse_line(char *ptr, char **varname, char **varval)
{
	/* Skip over any leading spaces */

	ptr = skip_space(ptr);

	/* The first no-space is the beginning of the variable name */

	*varname = skip_space(ptr);
	*varval = NULL;

	/* Parse to the end of the variable name */

	ptr = find_name_end(ptr);

	/* An equal sign is expected next, perhaps after some white space */

	if (*ptr && *ptr != '=') {
		/* Some else follows the variable name.  Terminate the variable
		 * name and skip over any spaces.
		 */

		*ptr = '\0';
		ptr = skip_space(ptr + 1);
	}

	/* Verify that the equal sign is present */

	if (*ptr == '=') {
		/* Make sure that the variable name is terminated (this was already
		 * done if the name was followed by white space.
		 */

		*ptr = '\0';

		/* The variable value should follow =, perhaps separated by some
		 * white space.
		 */

		ptr = skip_space(ptr + 1);
		if (*ptr) {
			/* Yes.. a variable follows.  Save the pointer to the start
			 * of the variable string.
			 */

			*varval = ptr;

			/* Find the end of the variable string and make sure that it
			 * is terminated.
			 */

			ptr = find_value_end(ptr);
			*ptr = '\0';
		}
	}
}

static char *dequote_value(const char *varname, char *varval)
{
	const char **dqnam;
	char *dqval = varval;
	int len;

	if (dqval) {
		/* Check if the variable name is in the list of strings to be dequoated */

		for (dqnam = dequote_list; *dqnam; dqnam++) {
			if (strcmp(*dqnam, varname) == 0)
				break;
		}

		/* Did we find the variable name in the list of configuration variables
		 * to be dequoated?
		 */

		if (*dqnam) {
			/* Yes... Check if there is a traiing quote */

			len = strlen(dqval);
			if (dqval[len - 1] == '"') {
				/* Yes... replace it with a terminator */

				dqval[len - 1] = '\0';
				len--;
			}

			/* Is there a leading quote? */

			if (dqval[0] == '"') {
				/* Yes.. skip over the leading quote */

				dqval++;
				len--;
			}

			/* Handle the case where nothing is left after dequoting */

			if (len <= 0)
				dqval = NULL;
		}
	}

	return dqval;
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

void generate_definitions(FILE * stream)
{
	char *varname;
	char *varval;
	char *ptr;

	/* Loop until the entire file has been parsed. */

	do {
		/* Read the next line from the file */

		ptr = read_line(stream);
		if (ptr) {
			/* Parse the line into a variable and a value field */

			parse_line(ptr, &varname, &varval);

			/* Was a variable name found? */

			if (varname) {
				/* Yes.. dequote the value if necessary */

				varval = dequote_value(varname, varval);

				/* If no value was provided or if the special value 'n' was provided,
				 * then undefine the configuration variable.
				 */

				if (!varval || strcmp(varval, "n") == 0)
					printf("#undef %s\n", varname);

				/* Simply define the configuration variable if it has the special
				 * value "y"
				 */

				else if (strcmp(varval, "y") == 0)
					printf("#define %s 1\n", varname);

				/* Otherwise, use the value as provided */

				else
					printf("#define %s %s\n", varname, varval);
			}
		}
	} while (ptr);
}
